1. Field of the Invention
The present invention is directed to a sealing device positioned between two elements of a turbomachine.
2. Description of the Prior Art
In order to ensure optimal control of the rate of leakage of cooling air, which is particularly critical on small engines, and of the migration of hot gases at the junction of a combustion chamber and a high pressure distributor support housing in a turbomachine, an effective seal must be created between these two elements.
The elements at the junction of the turbine nozzle and the combustion chamber most often have large relative axial and radial displacements. These displacements are generally created primarily by temperature differences between the elements in transitory operation and by differences in the expansion coefficients of the materials.
The deviations in stabilized operation are themselves less important, although they too are a function of the technology chosen. It should also be noted that these relative displacements in transitory and stabilized operation are not identical from one engine to the next as a result of manufacturing tolerances.
Leaktightness is generally assured by a fork-shaped assembled device, as shown by reference numerals 1 and 2 in FIG. 1, which represents a longitudinal cross-section of a portion of a turbomachine, the combustion chamber 3 of which is connected to support housing 4 of a turbine nozzle 5 by means of the assembly device. This fork-shaped assembled device requires narrowed adjustment tolerances, without it thereby being possible, in most cases, to control totally the operating play of the elements present and thus the rate of leakage.
There also exists a sealing device as represented in FIG. 2, in which combustion chamber 3 is connected to support housing 4 for turbine nozzle 5 by means of a fixed or movable side plate device 6 and 7. However, the side plate joint assembled apparatus requires still stricter and thus more costly tolerances while the diversity of the elements entails a cumulation of the number of tolerances (albeit small when taken individually) which is incompatible with the reduced, or totally absent, play necessary for satisfactory leaktightness.
A leaktight connection device which includes flanges and bolts is also known. Such a bolted device is simpler, but heavier, and in operation generates severe mechanical stress and does not always enable assembly and disassembly requirements to be met.